It is well-known, the oil resources around the world become increasingly depleted, and the development of human society causes great damage and pollution to the environment, which make countries around the world begin to look for more environmental, replaceable and renewable energy sources. Hydrogen, as one of the most abundant element in the universe, is clean, renewable and has high density of energy, and is considered the most promising replaceable energy source in the future. With the improvement of fuel cell technology, hydrogen energy has been used in the vehicles.
The hydrogen supply system is one of the most unsafe factors for hydrogen fuel cell vehicles. Hydrogen is of the lowest density, the most flammable, easy to explode, and of the highest energy among all gases, therefore, the above characteristics of the hydrogen can not be ignored, and in the world an important concept of “hydrogen safety” has been clearly presented in the beginning of developing hydrogen fuel cell vehicles. In the development of vehicle high-pressure hydrogen supply system, the same technical route is adopted almost all over the world, that is to continue the development foundation of the gas-supply system for natural gas vehicle, to use for reference its technique, criterions and standards, and to gradually improve it according to the characteristics of the vehicle high pressure hydrogen supply system. In order to improve the driving mileage of fuel cell vehicles, car manufacturers want to increase the work pressure of the hydrogen supply system from 20 MPa to 35 MPa, and further put forward the object of increasing to 70 MPa, so the security and reliability of the hydrogen supply system is particularly prominent and important.
In China, the research on the supply system of natural gas vehicles begins with the use of single fuel of natural gas in large scale on the buses in Beijing since 1999. The researches are mainly on the security and reliability of the system (failure mode, fault tree, dangers analysis and corrective measures). Automatic overflowing protection devices are added etc. Some corresponding utility models have been published, but there is no publication of inventions or other relating documents about the present low consumption and intelligent safe gas-supply system in which the gas tanks are opened in sequence; In other countries, the improvement of the natural gas vehicle gas-supply system is also mainly on the improvement of the security and reliability, and there are some corresponding publication of patents or public documents, but there is still no publication of patents or other relating documents about the present low consumption and intelligent safe gas-supply system in which the gas tanks are opened in sequence. For the gas storage pressure of gas tanks which is higher than 20 MPa (such as 35 MPa or more than 70 MPa), that the gas tanks are opened in sequence, so as to provide a safe, reliable, low consumption and intelligent gas-supply system for hydrogen fuel cell vehicle, is the developing direction and trend of the relating technical field and also the background requirements of the present invention.
In recent years, in China, the research on fuel cell vehicles develops greatly for further engineering practice. Hydrogen supply system is one of the most important research areas, and at present there is no publication of relating patents and papers; in other countries, the patent application “HYDROGEN VEHICLE GAS UTILIZATION AND REFUELING SYSTEM” which is invented by Steven R. Mathison and Shiro Matsuo's (the application number is US2006/0118175A1) is published in U.S. in June 2006. This application mainly describes the control structure of the high pressure hydrogen supply system for vehicle or gas filling station. In this application, the hydrogen storage system and supply system are connected to the gas tank valve respectively and are separated at the gas tank mouth, and the core of the protection is: when supplying gas to fuel cells, gas tank conduit is opened respectively, so as to improve the efficiency of gas extraction and reduce the left hydrogen ratio in the gas tank. There is a pressure sensor on every gas tank of gas tanks, which is used as the criterion for gas tank solenoid valve opening. This invention is different from the present invention, and their protecting contents are different, and this invention doesn't present any solution to the security.
To rapidly advance researches on engineering of fuel cell vehicle, further improve the atmospheric environment, and improve people's living quality, researches on the hydrogen supply system of the fuel cell vehicles must follow the direction of security, reliability, low consumption and intelligence, which are also the background requirements of the present invention.
The present invention can be applied to the vehicle hydrogen supply system in the fuel cell vehicle or the vehicle compressed natural gas supply system in the natural gas vehicle, and high-pressure hydrogen or natural gas supply system for gas tanks on the ground.